The MRI-Measured Arterial Input Function Resulting From a Bolus Injection of Gd-DTPA in a Rat Model of Stroke Slightly Underestimates That of Gd-[14C]DTPA and Marginally Overestimates the Blood-to-Brain Influx Rate Constant Determined by Patlak Plots
The MRI-Measured Arterial Input Function Resulting From a Bolus Injection of Gd-DTPA in a Rat Model of Stroke Slightly Underestimates That of Gd-[14C]DTPA and Marginally Overestimates the Blood-to-Brain Influx Rate Constant Determined by Patlak Plots
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DOI：
10.1002/mrm.22339
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发表时间：
2010-06-01
影响因子：
3.3
通讯作者：
Knight, Robert A.
中科院分区：
文献类型：
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作者：
Nagaraja, Tavarekere N.;Karki, Kishor;Knight, Robert A.
假设静脉推注钆-二乙烯三胺五乙酸的动脉输入功能（AIF）通过T（1）-舒张率的变化来测量，（Delta R（1）; R（1）= 1/T（1））的上级矢状窦血（AIF-I）近似于动脉血中测量的（14）C-标记钆-二乙烯三胺五乙酸的AIF在大鼠中风模型（n = 13）中测试AIF（参考AIF）。与假设相反，Delta R（1）-时间曲线的初始部分被低估了，AIF-I的标准化曲线下面积比参考AIF低约15%。钆-二亚乙基三胺五乙酸的假设AIF来自参考AIF值，并取平均值以获得队列平均AIF。使用AIF-I、假设AIF、队列平均AIF和组织Delta R（1）数据的Patlak图估计流入速率常数（K（i））和零时质子分布体积（V（p）+ V（o））。对于感兴趣的区域，使用AIF-I估计的K（i）略高于使用假设AIF和队列平均AIF获得的K（i），但不显著。相比之下，当使用AIF-I计算时，V（p）+ V（o）显著更高。K（i）和V（p）+ V（o）的估计值与假设的AIF和队列平均AIF相似。总之，AIF-I低估了参考AIF;这一缺陷对Patlak图计算的K（i）几乎没有影响，但显著高估了V（p）+ V（o）。Magn Reson Med 63：1502-1509，2010. (C)2010 Wiley-Liss，Inc.
The hypothesis that the arterial input function (AIF) of gadolinium-diethylenetriaminepentaacetic acid injected by intravenous bolus and measured by the change in the T(1)-relaxation rate (Delta R(1); R(1) = 1/T(1)) of superior sagittal sinus blood (AIF-I) approximates the AIF of (14)C-labeled gadolinium-diethylenetriaminepentaacetic acid measured in arterial blood (reference AIF) was tested in a rat stroke model (n = 13). Contrary to the hypothesis, the initial part of the Delta R(1)-time curve was underestimated, and the area under the normalized curve for AIF-I was about 15% lower than that for the reference AIF. Hypothetical AIFs for gadolinium-diethylenetriaminepentaacetic acid were derived from the reference AIF values and averaged to obtain a cohort-averaged AIF. Influx rate constants (K(i)) and proton distribution volumes at zero time (V(p) + V(o)) were estimated with Patlak plots of AIF-I, hypothetical AIFs, and cohort-averaged AIFs and tissue Delta R(1) data. For the regions of interest, the K(i)s estimated with AIF-I were slightly but not significantly higher than those obtained with hypothetical AIFs and cohort-averaged AIF. In contrast, V(p) + V(o) was significantly higher when calculated with AIF-I. Similar estimates of K(i) and V(p) + V(o) were obtained with hypothetical AIFs and cohort-averaged AIF. In summary, AIF-I underestimated the reference AIF; this shortcoming had little effect on the K(i) calculated by Patlak plot but produced a significant overestimation of V(p) + V(o). Magn Reson Med 63:1502-1509, 2010. (C) 2010 Wiley-Liss, Inc.